Multicolor, multilayer photographic elements are well known in the art. Such materials generally have three different selectively sensitized color records having one or more silver halide emulsion layers coated on one side of a single support. Each color record has components useful for forming a particular color in an image. Typically, the materials utilize color forming couplers or dyes in the sensitized layers during processing.
One commercially important type of color photographic elements are what are known as color prints. These elements are used to display images captured by a camera user on photographic color negative films. There is continuing interest in the industry to provide color print images more rapidly so the customers have a smaller wait from the time the color negative films are submitted for processing to the time they receive the color prints.
In color paper processing, the conventional order of the light sensitive color records on a support is a blue-sensitive silver halide emulsion layer nearest the support, a green-sensitive silver halide emulsion layer next to it, and a red-sensitive silver halide emulsion layer as the topmost light sensitive layer. It has been observed that the blue-sensitive emulsion layer is the slowest to achieve aim sensitometry, generally because it is the last layer to receive processing chemicals. Most color papers are designed in the various layers to take this into account and to provide desired correct color balance among the color records using standard processing conditions and times.
Pyrazolidone compounds are commonly used as black and white developing agents. They have also been incorporated as electron transfer agents into color photographic materials for various purposes, color development activity, as described in U.S. Pat. No. 4,266,002 (McCreary et al) and U.S. Pat. No. 4,465,762 (Ishikawa et al). Moreover, in EP 0 561 860B 1 (Twist) describes the use of pyrazolidones either in color photographic materials or color developers in order to reduce variabilities in sensitometric properties. Processing in this context is under standard times and temperatures. For example, color development was varied from 1 to 8 minutes. In U.S. Pat. No. 4,155,763 (Hasebe et al), 3-pyrazolidone derivatives are incorporated into color developing solutions for various purposes including alleged rapid color development. However, only color development at the relatively slow 60 seconds is shown.
However, as noted above, there is a need to reduce processing time, and particularly to reduce color development time. When conventional color papers are color developed in reduced times, for example, for less than 25 seconds, the red-sensitive color record is generally over developed and the blue-sensitive color record is underdeveloped. Reformulation of the conventional color developer chemicals to decrease activity in the red-sensitive color record towards the aim sensitometry only makes the blue-sensitive color record move lower and further from aim sensitometry. Reformulation of the conventional color developer chemicals to increase activity in the blue-sensitive color record towards aim sensitometry only makes the red-sensitive record move higher and further from aim sensitometry. Thus reformulation of the conventional color developer chemicals has not resulted in a solution to this problem and for short color development times, existing color papers give prints with unacceptable color balance. Moreover, it is not practical to change the color papers encountered in the trade, especially since they are available from several manufacturers.
Thus, there is a need to provide aim color balance in color photographic silver halide papers without reengineering the color papers or adversely affecting the color developing composition, no matter what time is used for color development. In particular, it is desired to achieve aim color balance during rapid color development.